<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        
        header {
            width: 1000px;
            height: 35px;
            margin: 0 auto;
            margin-top: 20px;
            background-color: #ccc;
        }
        
        .content {
            width: 1000px;
            height: 500px;
            margin: 10px auto;
            background-color: #ccc;
        }
        
        .footer {
            width: 1000px;
            height: 35px;
            margin: 0 auto;
            background-color: #ccc;
        }
    </style>
</head>

<body>
    <header>

    </header>


    <section class="content">

    </section>

    <footer class="footer">

    </footer>
</body>

</html>